FIG. 11 is a side view of a string-striking device 100 for a piano, comprising a key 110, a transmitting portion 120, and a hammer portion 130. Conventionally as seen in FIG. 11, in order to adjust the static loading, applied upon the key 110 depression, to a fore-end 111 on the playing side of the key 110, holes have been created on a side face 112 of the fore-end 111 on the playing side of the key 110 and leads 115, as plummets, have been buried therein. Additionally, for the impression of the sound of the key 110, the weight of the leads 115 has been adjusted so that the static loading of the key 110 is decreased gradually from the lower notes to the higher notes.
This static loading is sensed by a player of the piano as the touch and feel of the key 110. The static loading is an important parameter and how it is adjusted can determine whether the piano is considered good or bad. Thus, the static loading should be adjusted with caution in accordance with the skill and taste of the player.
In general, a string for a lower note is thicker than a string for a higher note. Therefore, a hammer 131 that strikes the string for a lower note is made larger and heavier than the hammer 131 for a higher note. Accordingly, the static loading for the lower note is heavier without the leads 115. Without the leads 115, however, especially in parts of the piano where two keys 110, residing next to each other, respectively have a different number of strings to strike, there is a problem in that the difference in the static loading between the two neighboring keys 110 becomes significantly large as compared to the case in other parts of the piano.
In the adjustment of the static loading, the weight of the leads 115 is selected to increase naturally within a reasonable range from the higher notes to the lower notes, taking into account such various factors. In this manner, the leads 115 are prepared for and attached to the respective keys 110 (see Patent Document 1, for example).
Patent Document 1: Japanese utility model publication No. 53-23219